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901.
张德祥 (2022-06-22 19:35):
#paper https://doi.org/10.1016/j.pbiomolbio.2022.05.006 A free energy principle for generic quantum systems 自由能作为一个无尺度的概念框架,这篇论文讲FEP的适用范围扩展到了一般的量子系统,论文表明量子生物的领域比现在了解的要大的多。预测分子级别的动力学实现了量子信息处理。技术细节没有基础,个人感觉难度比较大,欢迎朋友一起研读。
Abstract:
The Free Energy Principle (FEP) states that under suitable conditions of weak coupling, random dynamical systems with sufficient degrees of freedom will behave so as to minimize an upper bound, … >>>
The Free Energy Principle (FEP) states that under suitable conditions of weak coupling, random dynamical systems with sufficient degrees of freedom will behave so as to minimize an upper bound, formalized as a variational free energy, on surprisal (a.k.a., self-information). This upper bound can be read as a Bayesian prediction error. Equivalently, its negative is a lower bound on Bayesian model evidence (a.k.a., marginal likelihood). In short, certain random dynamical systems evince a kind of self-evidencing. Here, we reformulate the FEP in the formal setting of spacetime-background free, scale-free quantum information theory. We show how generic quantum systems can be regarded as observers, which with the standard freedom of choice assumption become agents capable of assigning semantics to observational outcomes. We show how such agents minimize Bayesian prediction error in environments characterized by uncertainty, insufficient learning, and quantum contextuality. We show that in its quantum-theoretic formulation, the FEP is asymptotically equivalent to the Principle of Unitarity. Based on these results, we suggest that biological systems employ quantum coherence as a computational resource and - implicitly - as a communication resource. We summarize a number of problems for future research, particularly involving the resources required for classical communication and for detecting and responding to quantum context switches. <<<
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902.
张德祥 (2022-06-22 19:20):
#paper DOI https://doi.org/10.1007/s11229-022-03480-w Active inference models do not contradict folk psychology 主动推理作为一个大框架,能否跟传统心理学中的各种高级概念兼容?这篇论文对两者进行了对比分析,结论是主动推理架构跟传统心理学的高级概念: 信念 愿望 意图兼容,虽然主动推理的数学中没有这些概念的直接定义,但是主动推理的公式中概念的含义可以跟这些高级心理概念对应。
Abstract:
AbstractActive inference offers a unified theory of perception, learning, and decision-making at computational and neural levels of description. In this article, we address the worry that active inference may be … >>>
AbstractActive inference offers a unified theory of perception, learning, and decision-making at computational and neural levels of description. In this article, we address the worry that active inference may be in tension with the belief–desire–intention (BDI) model within folk psychology because it does not include terms for desires (or other conative constructs) at the mathematical level of description. To resolve this concern, we first provide a brief review of the historical progression from predictive coding to active inference, enabling us to distinguish between active inference formulations of motor control (which need not have desires under folk psychology) and active inference formulations of decision processes (which do have desires within folk psychology). We then show that, despite a superficial tension when viewed at the mathematical level of description, the active inference formalism contains terms that are readily identifiable as encoding both the objects of desire and the strength of desire at the psychological level of description. We demonstrate this with simple simulations of an active inference agent motivated to leave a dark room for different reasons. Despite their consistency, we further show how active inference may increase the granularity of folk-psychological descriptions by highlighting distinctions between drives to seek information versus reward—and how it may also offer more precise, quantitative folk-psychological predictions. Finally, we consider how the implicitly conative components of active inference may have partial analogues (i.e., “as if” desires) in other systems describable by the broader free energy principle to which it conforms. <<<
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903.
颜林林 (2022-06-22 00:43):
#paper doi:10.1038/s41591-022-01768-5 Nature Medicine, 2022, Swarm learning for decentralized artificial intelligence in cancer histopathology. 前段时间刚在Nature上一篇文章(doi:10.1038/s41586-021-03583-3)读到Swarm learning(群体学习),该文提及一种在不违反隐私法规的前提下进行临床数据共享,从而帮助针对那些普遍存在异质性的疾病开展精准医学研究。本文则是针对肿瘤病理图像分析,也使用群体学习技术。病理图像分析,是典型的需要依赖大量高质量数据集的研究方向,群体学习正好使得合作单位可以共同训练AI模型,同时又避免数据传输和数据垄断。本文基于来自爱尔兰、德国和美国的三个结直肠癌患者队列训练了模型,该模型通过分析患者的H&E染色切片,预测其驱动基因突变、dMMR突变和微卫星不稳定性状态(MSI)等,并在来自英国的两个独立队列数据集中进行模型的性能验证。在训练模型的三个数据节点(研究中心)之间,并不直接传递原始数据,而是在每次迭代步骤中,通过去中心化的区块链技术,进行模型参数的同步。也因此,各数据节点之间是对等的,并没有需要汇总其他节点的特殊中心节点。这种模式为将来拓展到更大范围、更多机构的合作,提供了可能性,也将使病理图像分析模型得到更大进步。
IF:58.700Q1 Nature medicine, 2022-06. DOI: 10.1038/s41591-022-01768-5 PMID: 35469069 PMCID:PMC9205774
Abstract:
Artificial intelligence (AI) can predict the presence of molecular alterations directly from routine histopathology slides. However, training robust AI systems requires large datasets for which data collection faces practical, ethical … >>>
Artificial intelligence (AI) can predict the presence of molecular alterations directly from routine histopathology slides. However, training robust AI systems requires large datasets for which data collection faces practical, ethical and legal obstacles. These obstacles could be overcome with swarm learning (SL), in which partners jointly train AI models while avoiding data transfer and monopolistic data governance. Here, we demonstrate the successful use of SL in large, multicentric datasets of gigapixel histopathology images from over 5,000 patients. We show that AI models trained using SL can predict BRAF mutational status and microsatellite instability directly from hematoxylin and eosin (H&E)-stained pathology slides of colorectal cancer. We trained AI models on three patient cohorts from Northern Ireland, Germany and the United States, and validated the prediction performance in two independent datasets from the United Kingdom. Our data show that SL-trained AI models outperform most locally trained models, and perform on par with models that are trained on the merged datasets. In addition, we show that SL-based AI models are data efficient. In the future, SL can be used to train distributed AI models for any histopathology image analysis task, eliminating the need for data transfer. <<<
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904.
颜林林 (2022-06-21 00:03):
#paper doi:10.1016/j.jmoldx.2022.05.003 The Journal of Molecular Diagnostics, 2022, Comprehensive Validation of Diagnostic Next-Generation Sequencing Panels for Acute Myeloid Leukemia (AML) Patients. 这是来自瑞士和德国的一篇关于血液肿瘤基因检测panel验证的文章。通常认为,肿瘤是遗传病,即由于遗传物质发生突变而导致的疾病。因此,在诊断和治疗决策过程中,会需要开展特定基因的检测。在临床实践上,可以采取panel富集特定DNA片段进行测序的方法,这也是目前肿瘤相关基因检测商业服务的基本模式。这种检测服务得以上市的前提,是需要经过充分的验证。本文便是这样一个验证过程的实例。本文的验证对象,是为诊断AML(急性髓系白血病)的panel,验证过程纳入了26例AML患者的33个DNA样本(骨髓或外周血),以及Acrometrix Oncology Hotspot Control DNA作为对照。对这些样本中携带的AML相关突变进行了检测和性能评价。而临床样本中的突变,也采用qPCR、Sanger测序等方法进行了确认。通过评估,从四个不同panel及多种分析软件中,选出了针对血液病性能最佳的panel及软件组合。
Abstract:
Next-generation sequencing has greatly advanced the molecular diagnostics of malignant hematological diseases and provides useful information for clinical decision making. Studies have shown that certain mutations are associated with prognosis … >>>
Next-generation sequencing has greatly advanced the molecular diagnostics of malignant hematological diseases and provides useful information for clinical decision making. Studies have shown that certain mutations are associated with prognosis and have a direct impact on treatment of affected patients. Therefore, reliable detection of pathogenic variants is critically important. Here, we compared four sequencing panels with different characteristics, from number of genes covered to technical aspects of library preparation and data analysis workflows, to find the panel with the best clinical utility for myeloid neoplasms with a special focus on acute myeloid leukemia. Using the Acrometrix Oncology Hotspot Control DNA and DNA from acute myeloid leukemia patients, panel performance was evaluated in terms of coverage, precision, recall, and reproducibility and different bioinformatics tools that can be used for the evaluation of any next-generation sequencing panel were tested. Taken together, our results support the reliability of the Acrometrix Oncology Hotspot Control to validate and compare sequencing panels for hematological diseases and show which panel-software combination (platform) has the best performance. <<<
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905.
张浩彬 (2022-06-20 08:27):
#paper doi:10.1145/3219819.3219822,Deep Distributed Fusion Network for Air Quality Prediction .2018年的kdd论文,从现在的角度看,或者从当时的角度看,作者所构建的这个网络都并不复杂。这个网络主要包括2个组件:空间变换组件以及深度分布融合组件。 1.设计了一个空间变换组件,将空间稀疏的空气质量数据转换为模拟二手污染物源的一致输入, 借助来自空间邻居的信号(根据分布方位分为远近及东西南北向供16个),DeepAir 在一般情况和突变情况下具有更好的性能。 2.考虑到直接和间接因素对空气质量的影响不同,分别使用每个间接因素与直接因素进行一个子网络构建,以及构建一个整体子网络,最后进行融合。。  3.这个论文的网络结构虽然不复杂,但是却很贴近业务。是基于业务的基础上对网络进行设计的。作者基于 9 个中国城市的三年数据,结果表明 DeepAir 与 10 个基线相比具有优势。 在短期、长期和突变预测方面的相对准确度分别提高了 2.4%、12.2%、63.2%。
Abstract:
Accompanying the rapid urbanization, many developing countries are suffering from serious air pollution problem. The demand for predicting future air quality is becoming increasingly more important to government's policy-making and … >>>
Accompanying the rapid urbanization, many developing countries are suffering from serious air pollution problem. The demand for predicting future air quality is becoming increasingly more important to government's policy-making and people's decision making. In this paper, we predict the air quality of next 48 hours for each monitoring station, considering air quality data, meteorology data, and weather forecast data. Based on the domain knowledge about air pollution, we propose a deep neural network (DNN)-based approach (entitled DeepAir), which consists of a spatial transformation component and a deep distributed fusion network. Considering air pollutants' spatial correlations, the former component converts the spatial sparse air quality data into a consistent input to simulate the pollutant sources. The latter network adopts a neural distributed architecture to fuse heterogeneous urban data for simultaneously capturing the factors affecting air quality, e.g. meteorological conditions. We deployed DeepAir in our AirPollutionPrediction system, providing fine-grained air quality forecasts for 300+ Chinese cities every hour. The experimental results on the data from three-year nine Chinese-city demonstrate the advantages of DeepAir beyond 10 baseline methods. Comparing with the previous online approach in AirPollutionPrediction system, we have 2.4%, 12.2%, 63.2% relative accuracy improvements on short-term, long-term and sudden changes prediction, respectively. <<<
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906.
颜林林 (2022-06-20 07:48):
#paper doi:10.1016/j.gpb.2022.03.002 Genomics, Proteomics & Bioinformatics, 2022, Cancer is a survival process under persistent microenvironmental and cellular stresses. 这篇综述是关于癌症发生发展的机制,提出了一个新的框架看法。相较于传统以突变为核心的理解,该新看法的关键点在于,认为癌细胞的持续分裂是其生存的“必须”行为,而非仅受遗传物质突变所指导的被动结果。针对这个看法,文章从代谢模式变化、胞质pH状态、慢性炎症、过量铁积累负荷、芬顿反应等角度分别进行了阐释。对于某些癌种随年龄增长其发病率反而下降,以及某些物种很少发生或几乎不会发生癌症,这种看法也提供了新的解释。
907.
颜林林 (2022-06-19 00:14):
#paper doi:10.1186/s13073-022-01069-z Genome Medicine, 2022, Reanalysis of exome negative patients with rare disease: a pragmatic workflow for diagnostic applications. 过去这些年里,我们经常会对罕见遗传病患者开展全外显子组测序,以便确认其致病基因并形成诊断结论。然而,受限于技术和积累的知识,大部分患者在测序后也仍然无法确诊。这篇来自荷兰拉德堡德大学(Radboud University)的文章,回顾了其医学中心在2011年11月至2015年1月期间到访的疑似罹患复杂神经系统遗传疾病的150名儿童患者,对其中103名未得到确诊的患者进行了随访调查,通过重新查阅评估表型信息、重新分析其全外显子测序数据,以及对仍无法确诊的患者(使用新的实验流程和外显子panel)重新进行测序和分析。这一系列操作,让32名之前未被诊断的患者得到确诊,诊断率从31%(47/150)提升到53%(79/150)。其结果也支持了在临床护理和后续随访过程中,应该对未确诊患者进行重新分析和系统评估,新的临床证据信息、新的技术方法和分析方法,都有助于改善诊治,使患者获益。
IF:10.400Q1 Genome medicine, 2022-06-17. DOI: 10.1186/s13073-022-01069-z PMID: 35710456
Abstract:
BACKGROUND: Approximately two third of patients with a rare genetic disease remain undiagnosed after exome sequencing (ES). As part of our post-test counseling procedures, patients without a conclusive diagnosis are … >>>
BACKGROUND: Approximately two third of patients with a rare genetic disease remain undiagnosed after exome sequencing (ES). As part of our post-test counseling procedures, patients without a conclusive diagnosis are advised to recontact their referring clinician to discuss new diagnostic opportunities in due time. We performed a systematic study of genetically undiagnosed patients 5 years after their initial negative ES report to determine the efficiency of diverse reanalysis strategies.METHODS: We revisited a cohort of 150 pediatric neurology patients originally enrolled at Radboud University Medical Center, of whom 103 initially remained genetically undiagnosed. We monitored uptake of physician-initiated routine clinical and/or genetic re-evaluation (ad hoc re-evaluation) and performed systematic reanalysis, including ES-based resequencing, of all genetically undiagnosed patients (systematic re-evaluation).RESULTS: Ad hoc re-evaluation was initiated for 45 of 103 patients and yielded 18 diagnoses (including 1 non-genetic). Subsequent systematic re-evaluation identified another 14 diagnoses, increasing the diagnostic yield in our cohort from 31% (47/150) to 53% (79/150). New genetic diagnoses were established by reclassification of previously identified variants (10%, 3/31), reanalysis with enhanced bioinformatic pipelines (19%, 6/31), improved coverage after resequencing (29%, 9/31), and new disease-gene associations (42%, 13/31). Crucially, our systematic study also showed that 11 of the 14 further conclusive genetic diagnoses were made in patients without a genetic diagnosis that did not recontact their referring clinician.CONCLUSIONS: We find that upon re-evaluation of undiagnosed patients, both reanalysis of existing ES data as well as resequencing strategies are needed to identify additional genetic diagnoses. Importantly, not all patients are routinely re-evaluated in clinical care, prolonging their diagnostic trajectory, unless systematic reanalysis is facilitated. We have translated our observations into considerations for systematic and ad hoc reanalysis in routine genetic care. <<<
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908.
颜林林 (2022-06-18 14:39):
#paper doi:10.1021/acssynbio.2c00120 ACS Synthetic Biology, 2022, Graph Computation Using Algorithmic Self-Assembly of DNA Molecules. 利用DNA等生物分子进行计算,可以追溯至上世纪90年代初,该领域这些年来不断进步并取得新成果,本文便是这样的一个案例。本文另辟蹊径,使用了一种称为DNA折纸的技术(即通过精巧地设计DNA序列,使其折叠成为某种特定形状),来解决一个“六顶点三色涂色”的图论计算问题。宏观上极少量的生物物质,其实包含着数量庞大的分子,因而,使用这些分子进行计算,是一个天然能提供巨大算力的策略,可以很轻松实现大量排列组合的暴力穷举,这就是生物计算概念提出的基本出发点之一。虽说被称为“DNA computing”,但它其实还远不及我们日常认识的通用电子计算机。本文的研究,是在特定图论问题上,人为列举出各个待求顶点的所有可能颜色,以及利用DNA链互补特性,设计相应序列,实现控制哪些顶点之间可以互相连接的规则。然后大量合成这样的分子,使其在特定实验条件下自由组合,最终利用AFM(原子力显微镜)扫描,找到符合特定结构形状的答案。由于使用了DNA折纸技术,AFM可以直接观察并识别出各顶点的“颜色”及连接组合,从而给出问题的求解。文章所解决的问题,被限定在特定范围,且只是概念验证阶段,未来要扩展到更多应用场景,使其具备“通用”或一定程度“通用”的程度,还有很长的路要走。
IF:3.700Q1 ACS synthetic biology, 2022-07-15. DOI: 10.1021/acssynbio.2c00120 PMID: 35703038
Abstract:
DNA molecules have been used as novel computing tools, by which Synthetic DNA was designed to execute computing processes with a programmable sequence. Here, we proposed a parallel computing method … >>>
DNA molecules have been used as novel computing tools, by which Synthetic DNA was designed to execute computing processes with a programmable sequence. Here, we proposed a parallel computing method using DNA origamis as agents to solve the three-color problem, an example of the graph problem. Each agent was fabricated with a DNA origami of ∼50 nm diameter and contained DNA probes with programmable sticky ends that execute preset computing processes. With the interaction of different nanoagents, DNA molecules self-assemble into spatial nanostructures, which embody the computation results of the three-color problem with polynomial numbers of computing nanoagents in a one-pot annealing step. The computing results were confirmed by atomic force microscopy. Our method is completely different from existing DNA computing methods in its computing algorithm, and it has an advantage in terms of computational complexity and results detection for solving graph problems. <<<
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909.
颜林林 (2022-06-17 22:10):
#paper doi:10.1101/2022.06.12.495839 bioRxiv, 2022, Accurate Estimation of Molecular Counts from Amplicon Sequence Data with Unique Molecular Identifiers. 高通量测序数据中充满由PCR扩增和测序过程导致的错误,为解决此问题,人们通常会引入分子标签(UMI)技术,即用一段随机序列来标记出哪些序列来自同一原始模板分子,而哪些不是。很多工具在处理UMI时,都简单粗暴地将相同UMI的序列直接进行合并,而由于UMI序列本身也存在突变,会导致还原样本中原始模板分子信息的过程被误判。这个过程在扩增子测序(amplicon-seq)中尤为明显。本文通过构建一个单步隐马科夫模型(one step HMM),来处理PCR和测序过程中的错误,并用C语言实现了一套EM算法,对UMI测序数据的真实原始模板分子数进行估算。在模拟数据和真实数据中,分别进行了评测,对比既往其他类似工具,本文开发的工具(DAUMI),能有效识别出UMI冲突(UMI collision),表现出更优异的性能。
Abstract:
Motivation: Amplicon sequencing is widely applied to explore heterogeneity and rare variants in genetic populations. Resolving true biological variants and quantifying their abundance is crucial for downstream analyses, but measured … >>>
Motivation: Amplicon sequencing is widely applied to explore heterogeneity and rare variants in genetic populations. Resolving true biological variants and quantifying their abundance is crucial for downstream analyses, but measured abundances are distorted by stochasticity and bias in amplification, plus errors during Polymerase Chain Reaction (PCR) and sequencing. One solution attaches Unique Molecular Identifiers (UMIs) to sample sequences before amplification eliminating amplification bias by clustering reads on UMI and counting clusters to quantify abundance. While modern methods improve over naive clustering by UMI identity, most do not account for UMI reuse, or collision, and they do not adequately model PCR and sequencing errors in the UMIs and sample sequences. Results: We introduce Deduplication and accurate Abundance estimation with UMIs (DAUMI), a probabilistic framework to detect true biological sequences and accurately estimate their deduplicated abundance from amplicon sequence data. DAUMI recognizes UMI collision, even on highly similar sequences, and detects and corrects most PCR and sequencing errors in the UMI and sampled sequences. We demonstrate DAUMI performs better on simulated and real data compared to other UMI-aware clustering methods. Availability: Source code is available at https://github.com/xiyupeng/AmpliCI-UMI. <<<
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910.
颜林林 (2022-06-16 00:40):
#paper doi:10.1038/s41588-022-01075-2 Nature Genetics, 2022, Allelic imbalance of chromatin accessibility in cancer identifies candidate causal risk variants and their mechanisms. 这又是一篇只有两位作者署名的论文。如今,司空见惯了一篇文章动辄好几十位甚至成百上千位作者的情况,见到这类一两位作者“单打独斗”的作品,还是挺佩服的。从这篇文章,我学到个新词“调节组(regulome)”;相应地,其关联分析方法,被称为“regulome-wide associations study (RWAS)”。这篇文章还有个特点,它并未通过湿实验产出新数据,而是完全使用公开数据进行分析,包括结果验证,也是在公共数据库中进行。从概念到方法上进行创新,而成果发表到Nature子刊上,挺值得学习的。作者使用了来自TCGA的406例ATAC-seq数据,涵盖23个不同癌种,识别出7262个胚系allele-specific accessibility QTLs (as-aQTLs),即把染色质开放程度当做一种数量性状来研究,这个aQTL也是仿照eQTL提出的概念,的确很有意思。而通过RWAS,在各个癌种中鉴别出与癌症发生风险相关的as-aQTL位点,且发现它们在癌症风险遗传力方面的富集度甚至优于其他功能注释。这不仅实现了对非编码的“垃圾DNA(junk DNA)”区间的功能研究和解释,也开辟了肿瘤治疗的新思路,即针对这些调控区间及其相关机制来开展治疗。
IF:31.700Q1 Nature genetics, 2022-06. DOI: 10.1038/s41588-022-01075-2 PMID: 35697866
Abstract:
While many germline cancer risk variants have been identified through genome-wide association studies (GWAS), the mechanisms by which these variants operate remain largely unknown. Here we used 406 cancer ATAC-Seq … >>>
While many germline cancer risk variants have been identified through genome-wide association studies (GWAS), the mechanisms by which these variants operate remain largely unknown. Here we used 406 cancer ATAC-Seq samples across 23 cancer types to identify 7,262 germline allele-specific accessibility QTLs (as-aQTLs). Cancer as-aQTLs had stronger enrichment for cancer risk heritability (up to 145 fold) than any other functional annotation across seven cancer GWAS. Most cancer as-aQTLs directly altered transcription factor (TF) motifs and exhibited differential TF binding and gene expression in functional screens. To connect as-aQTLs to putative risk mechanisms, we introduced the regulome-wide associations study (RWAS). RWAS identified genetically associated accessible peaks at >70% of known breast and prostate loci and discovered new risk loci in all examined cancer types. Integrating as-aQTL discovery, motif analysis and RWAS identified candidate causal regulatory elements and their probable upstream regulators. Our work establishes cancer as-aQTLs and RWAS analysis as powerful tools to study the genetic architecture of cancer risk. <<<
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911.
Ricardo (2022-06-15 21:04):
#paper https://doi.org/10.1016/j.neuroimage.2022.119297. A deep learning-based multisite neuroimage harmonization framework established with a traveling-subject dataset. 分享一篇师弟与我合作发表的工作。多中心效应在不同的研究领域都是一件非常难解决的问题,比如在脑磁共振成像研究中观察到的显著效应及其得出的结构功能特征在不同中心的数据上会得出不一致的结果。这篇文章提出了一个深度学习框架,利用特征解耦的建模方式分离与脑结构无关的站点特征和仅与脑结构有关的生物特征。这个方法可以显著消除灰质图的中心差异,并且编码器部分有效的编码了与站点效应有关的抽象特征以及与大脑结构有关的特征。
IF:4.700Q1 NeuroImage, 2022-08-15. DOI: 10.1016/j.neuroimage.2022.119297 PMID: 35568346
Abstract:
The accumulation of multisite large-sample MRI datasets collected during large brain research projects in the last decade has provided critical resources for understanding the neurobiological mechanisms underlying cognitive functions and … >>>
The accumulation of multisite large-sample MRI datasets collected during large brain research projects in the last decade has provided critical resources for understanding the neurobiological mechanisms underlying cognitive functions and brain disorders. However, the significant site effects observed in imaging data and their derived structural and functional features have prevented the derivation of consistent findings across multiple studies. The development of harmonization methods that can effectively eliminate complex site effects while maintaining biological characteristics in neuroimaging data has become a vital and urgent requirement for multisite imaging studies. Here, we propose a deep learning-based framework to harmonize imaging data obtained from pairs of sites, in which site factors and brain features can be disentangled and encoded. We trained the proposed framework with a publicly available traveling subject dataset from the Strategic Research Program for Brain Sciences (SRPBS) and harmonized the gray matter volume maps derived from eight source sites to a target site. The proposed framework significantly eliminated intersite differences in gray matter volumes. The embedded encoders successfully captured both the abstract textures of site factors and the concrete brain features. Moreover, the proposed framework exhibited outstanding performance relative to conventional statistical harmonization methods in terms of site effect removal, data distribution homogenization, and intrasubject similarity improvement. Finally, the proposed harmonization network provided fixable expandability, through which new sites could be linked to the target site via indirect schema without retraining the whole model. Together, the proposed method offers a powerful and interpretable deep learning-based harmonization framework for multisite neuroimaging data that can enhance reliability and reproducibility in multisite studies regarding brain development and brain disorders. <<<
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912.
颜林林 (2022-06-15 06:27):
#paper doi:10.1186/s12859-022-04783-y BMC Bioinformatics, 2022, CancerNet: a unified deep learning network for pan-cancer diagnostics. 这篇文章建立了一个通用的深度神经网络模型,基于来自TCGA的33种癌症的甲基化数据,检测癌症及其起源组织。同样的任务在2022年已有相应工作,能够达到96%的总体准确率。本文则通过同时使用无监督与有监督的方法,让模型在输出34个分类结果(33个癌种+1个正常非癌)的同时,也额外生成一组重新构造的CpG岛甲基化信息,并将生成的此信息,与用于模型输入的CpG到甲基化信息进行比对,损失函数中同时纳入了该比对差异。通过这种方式,模型整体性能得到进一步提高,总体准确率达到99.6%。此外,本文也同时考察了年龄、转移等混杂因素对模型的影响,并为未来研究和开发模型的可解释性提供了基础。整个研究基于OSF(开放科学框架)进行,数据和源代码都完全开放,是一份不错的学习材料。
IF:2.900Q1 BMC bioinformatics, 2022-Jun-13. DOI: 10.1186/s12859-022-04783-y PMID: 35698059
Abstract:
BACKGROUND: Despite remarkable advances in cancer research, cancer remains one of the leading causes of death worldwide. Early detection of cancer and localization of the tissue of its origin are … >>>
BACKGROUND: Despite remarkable advances in cancer research, cancer remains one of the leading causes of death worldwide. Early detection of cancer and localization of the tissue of its origin are key to effective treatment. Here, we leverage technological advances in machine learning or artificial intelligence to design a novel framework for cancer diagnostics. Our proposed framework detects cancers and their tissues of origin using a unified model of cancers encompassing 33 cancers represented in The Cancer Genome Atlas (TCGA). Our model exploits the learned features of different cancers reflected in the respective dysregulated epigenomes, which arise early in carcinogenesis and differ remarkably between different cancer types or subtypes, thus holding a great promise in early cancer detection.RESULTS: Our comprehensive assessment of the proposed model on the 33 different tissues of origin demonstrates its ability to detect and classify cancers to a high accuracy (> 99% overall F-measure). Furthermore, our model distinguishes cancers from pre-cancerous lesions to metastatic tumors and discriminates between hypomethylation changes due to age related epigenetic drift and true cancer.CONCLUSIONS: Beyond detection of primary cancers, our proposed computational model also robustly detects tissues of origin of secondary cancers, including metastatic cancers, second primary cancers, and cancers of unknown primaries. Our assessment revealed the ability of this model to characterize pre-cancer samples, a significant step forward in early cancer detection. Deployed broadly this model can deliver accurate diagnosis for a greatly expanded target patient population. <<<
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913.
颜林林 (2022-06-14 00:32):
#paper doi:10.1002/humu.24378 Human Mutation, 2022, Short amplicon reverse transcription-polymerase chain reaction detects aberrant splicing in genes with low expression in blood missed by ribonucleic acid sequencing analysis for clinical diagnosis. 这篇文章的标题很守规矩,把一大堆缩写都展开写全了,害我仔细辨认了半天:“reverse transcription-polymerase chain reaction” 其实是 rt-PCR,“ribonucleic acid sequencing” 其实是 RNA-seq。原来这是个说明“在某些情况下,rt-PCR相比RNA-seq更好”的故事。文章从另一个研究(Splicing and Disease Research Study)中选出了13个实际临床病例,它们在一些血液中通常低表达的基因上,已知存在诸如“外显子跳跃”这样的剪切相关突变,将这些病例的外周血样本,提取RNA后,分别进行RNA-seq和rt-PCR,确认了短片段rt-PCR的确能够有效且更灵敏地检出这些突变,而在RNA-seq中因为表达量太低而难以检出。从而验证了短片段rt-PCR方法可用于此类低表达基因的剪切相关突变的检测。
IF:3.300Q2 Human mutation, 2022-07. DOI: 10.1002/humu.24378 PMID: 35476365
Abstract:
Use of blood RNA sequencing (RNA-seq) as a splicing analysis tool for clinical interpretation of variants of uncertain significance (VUSs) found via whole-genome and exome sequencing can be difficult for … >>>
Use of blood RNA sequencing (RNA-seq) as a splicing analysis tool for clinical interpretation of variants of uncertain significance (VUSs) found via whole-genome and exome sequencing can be difficult for genes that have low expression in the blood due to insufficient read count coverage aligned to specific genes of interest. Here, we present a short amplicon reverse transcription-polymerase chain reaction(RT-PCR) for the detection of genes with low blood expression. Short amplicon RT-PCR, is designed to span three exons where an exon harboring a variant is flanked by one upstream and one downstream exon. We tested short amplicon RT-PCRs for genes that have median transcripts per million (TPM) values less than one according to the genotype-tissue expression database. Median TPM values of genes analyzed in this study are SYN1 = 0.8549, COL1A1 = 0.6275, TCF4 = 0.4009, DSP = .2894, TTN = 0.2851, COL5A2 = 0.1036, TERT = 0.04452, NTRK2 = 0.0344, ABCA4 = 0.00744, PRPH = 0, and WT1 = 0. All these genes show insufficient exon-spanning read coverage in our RNA-seq data to allow splicing analysis. We successfully detected all genes tested except PRPH and WT1. Aberrant splicing was detected in SYN1, TCF4, NTRK2, TTN, and TERT VUSs. Therefore, our results show short amplicon RT-PCR is a useful alternative for the analysis of splicing events in genes with low TPM in blood RNA for clinical diagnostics. <<<
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914.
颜林林 (2022-06-13 05:47):
#paper doi:10.1038/s41588-022-01082-3 Nature Genetics, 2022, Genomic analysis defines clonal relationships of ductal carcinoma in situ and recurrent invasive breast cancer. 本文研究导管原位癌(DCIS)。该疾病常见于乳腺癌筛查,即使经过治疗,也仍然有小部分患者会恶化复发成为浸润性乳腺癌。本文试图研究,恶化的这些患者,是否都来自原发性DCIS的复发克隆,亦或仅是新发的无关疾病。为此,本研究纳入了129对DCIS复发病例样本(即原位DCIS样本和复发样本;同时也包含匹配的癌旁对照组织),通过开展全外显子组测序、SNP芯片检测或靶向基因组panel测序(这里技术平台方法存在差别,是因为样本及其实验,分别来自和开展于荷兰、英国和美国的三家不同单位),进行基因组突变分析和拷贝数变异分析。同时也从中选取了4例病例,将其原发与复发组织,分别进行解离并开展单细胞基因组测序。针对这两种策略,都分别进行了克隆演化分析,最终确认并非所有同侧浸润性乳腺癌都与先前的 DCIS 有克隆相关性,其中有约五分之一其实为新发原发性癌症。此结果也在更大范围且更详细的程度上,验证了前人的研究结果。
IF:31.700Q1 Nature genetics, 2022-06. DOI: 10.1038/s41588-022-01082-3 PMID: 35681052
Abstract:
Ductal carcinoma in situ (DCIS) is the most common form of preinvasive breast cancer and, despite treatment, a small fraction (5-10%) of DCIS patients develop subsequent invasive disease. A fundamental … >>>
Ductal carcinoma in situ (DCIS) is the most common form of preinvasive breast cancer and, despite treatment, a small fraction (5-10%) of DCIS patients develop subsequent invasive disease. A fundamental biologic question is whether the invasive disease arises from tumor cells in the initial DCIS or represents new unrelated disease. To address this question, we performed genomic analyses on the initial DCIS lesion and paired invasive recurrent tumors in 95 patients together with single-cell DNA sequencing in a subset of cases. Our data show that in 75% of cases the invasive recurrence was clonally related to the initial DCIS, suggesting that tumor cells were not eliminated during the initial treatment. Surprisingly, however, 18% were clonally unrelated to the DCIS, representing new independent lineages and 7% of cases were ambiguous. This knowledge is essential for accurate risk evaluation of DCIS, treatment de-escalation strategies and the identification of predictive biomarkers. <<<
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915.
张德祥 (2022-06-12 23:52):
#paper DOI: https://doi.org/10.1016/j.jmp.2021.102632 A step-by-step tutorial on active inference and its application to empirical data 零基础入门自由能理论框架及代码编程细节,本论文从自由能基础开始介绍,以构建马尔科夫模型为中心,以落地掌握应用为目标,使用matlab代码,也介绍有开源python代码,有基础讲解也有高阶功能介绍,有层级模型的解读,内容还是比较多,深入下去看需要很大功夫。关键点推荐参考:https://mp.weixin.qq.com/s/FlqNQzCphhefOlgDD6vL9g
Abstract:
The active inference framework, and in particular its recent formulation as a partially observable Markov decision process (POMDP), has gained increasing popularity in recent years as a useful approach for … >>>
The active inference framework, and in particular its recent formulation as a partially observable Markov decision process (POMDP), has gained increasing popularity in recent years as a useful approach for modeling neurocognitive processes. This framework is highly general and flexible in its ability to be customized to model any cognitive process, as well as simulate predicted neuronal responses based on its accompanying neural process theory. It also affords both simulation experiments for proof of principle and behavioral modeling for empirical studies. However, there are limited resources that explain how to build and run these models in practice, which limits their widespread use. Most introductions assume a technical background in programming, mathematics, and machine learning. In this paper we offer a step-by-step tutorial on how to build POMDPs, run simulations using standard MATLAB routines, and fit these models to empirical data. We assume a minimal background in programming and mathematics, thoroughly explain all equations, and provide exemplar scripts that can be customized for both theoretical and empirical studies. Our goal is to provide the reader with the requisite background knowledge and practical tools to apply active inference to their own research. We also provide optional technical sections and multiple appendices, which offer the interested reader additional technical details. This tutorial should provide the reader with all the tools necessary to use these models and to follow emerging advances in active inference research. <<<
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916.
颜林林 (2022-06-12 07:49):
#paper doi:10.1038/s41598-022-13336-5 Scientific Reports, 2022, Omics-based integrated analysis identified IKZF2 as a biomarker associated with lupus nephritis. 相信很多人知道系统性红斑狼疮(SLE)这个疾病,跟我一样都来自二十多年前的一部火遍大江南北的虐心小说《第一次亲密接触》。而这篇文章所研究的,正是SLE的重要并发症和主要致死因素狼疮性肾炎(LN)。本文收集并挖掘了肾脏组织的公共数据,包括LN患者的肾小管间质和肾小体组织,也包括肾移植捐献者的健康肾组织,由这些数据找到26个常见差异表达基因(co-DEGs)。在此基础上,将其中的 IKZF2 基因作为重点,通过功能富集、蛋白-蛋白相互作用网络、ceRNA网络构建、免疫浸润、风险评估等常用生信方法进行分析,从而确定了 IKZF2 基因在 LN 疾病方面的预测和评估价值。文章的方法本身没有多少亮点,属于常见的套路玩法,应该是所选择的临床问题,为其提供了一定创新性和研究价值。
IF:3.800Q1 Scientific reports, 2022-06-10. DOI: 10.1038/s41598-022-13336-5 PMID: 35688845
Abstract:
Lupus nephritis (LN) is a crucial complication of systemic lupus erythematosus (SLE). IKZF2 was identified as a lupus susceptibility locus, while its exact molecular function in LN is unknown. We … >>>
Lupus nephritis (LN) is a crucial complication of systemic lupus erythematosus (SLE). IKZF2 was identified as a lupus susceptibility locus, while its exact molecular function in LN is unknown. We aimed to explore the relationship between IKZF2 and LN based on multi-omics data. In our study, we carried out a meta-analysis of publicly available data, including not only tubulointerstitium, but also glomerulus tissue samples from LN patients and controls. Based on the common differentially expressed genes (co-DEGs) and previous researches, we selected IKZF2 for further analysis. Then, we analyzed potential molecular mechanisms of co-DEGs and IKZF2 in LN. To explore the possible targets of IKZF2, protein-protein interaction network (PPI) network and ceRNA network of IKZF2 were also constructed. Moreover, we performed immune infiltration analysis and evaluated clinical value of IKZF2. A total of 26 co-DEGs were observed in the integration of the above DEGs coming from the four sets of data, of which IKZF2 was selected for further analysis. Functional enrichment analysis from IKZF2 and related PPI network confirmed the tight relationship between IKZF2 and the immune reaction. Moreover, immune filtration analysis revealed the significant correlation between IKZF2 and naïve B cell, NK cell activation, NK cell rest and other immune cells. Receiver operating characteristic (ROC) analysis showed that the areas under the ROC curves were 0.721, 0.80, 0.682, and 0.859 for IKZF2 in four datasets, which demonstrated the clinical value of IKZF2. Our study revealed that IKZF2 may play an essential role in the molecular function and development of LN, and might be a potential biomarker for distinguishing LN patients and healthy ones. <<<
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917.
张德祥 (2022-06-11 20:31):
#paper DOI https://doi.org/10.1007/s13164-021-00579-w Active Inference as a Computational Framework for Consciousness 意识作为一个复杂的现象,对它的研究应该梳理好研究方法,研究思路,研究框架,研究;自由能作为一个统一的框架,包括主动推理,预测过程等,对意识研究提供了整合的帮助,包括因果反事实,层次框架等,这篇论文对此进行了相关阐述,罗列了相关实验,可以参考:https://mp.weixin.qq.com/s/q7dsFAXTz00-rfdz6Qlw8A
Abstract:
Recently, the mechanistic framework of active inference has been put forward as a principled foundation to develop an overarching theory of consciousness which would help address conceptual disparities in the … >>>
Recently, the mechanistic framework of active inference has been put forward as a principled foundation to develop an overarching theory of consciousness which would help address conceptual disparities in the field (Wiese 2018; Hohwy and Seth 2020). For that promise to bear out, we argue that current proposals resting on the active inference scheme need refinement to become a process theory of consciousness. One way of improving a theory in mechanistic terms is to use formalisms such as computational models that implement, attune and validate the conceptual notions put forward. Here, we examine how computational modelling approaches have been used to refine the theoretical proposals linking active inference and consciousness, with a focus on the extent and success to which they have been developed to accommodate different facets of consciousness and experimental paradigms, as well as how simulations and empirical data have been used to test and improve these computational models. While current attempts using this approach have shown promising results, we argue they remain preliminary in nature. To refine their predictive and structural validity, testing those models against empirical data is needed i.e., new and unobserved neural data. A remaining challenge for active inference to become a theory of consciousness is to generalize the model to accommodate the broad range of consciousness explananda; and in particular to account for the phenomenological aspects of experience. Notwithstanding these gaps, this approach has proven to be a valuable avenue for theory advancement and holds great potential for future research. <<<
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918.
颜林林 (2022-06-11 14:48):
#paper doi:10.1016/j.cell.2022.04.016 Cell, 2022, Structural basis for RNA surveillance by the human nuclear exosome targeting (NEXT) complex. 这篇发表在最新一期《Cell》杂志上的文章,来自MSKCC(纪念斯隆·凯特琳癌症中心),仅有两位署名作者,M. Rhyan Puno 和 Christopher D. Lima。这项研究主要是基于冷冻电镜(cryo-EM),研究人细胞核外切体靶向(NEXT)复合物的分子结构。标题中的exosome是包含多种核酸外切酶的蛋白复合体,在细胞中起到外切和降解RNA的作用,是关乎RNA分子生存期及细胞内稳态的重要机制。另一个在液体活检领域常见的概念“外泌体”英文单词也是exosome,但其为包裹和使细胞向外分泌蛋白与核酸等分子的具有磷酸双分子层膜的囊泡结构,与此篇文章的exosome无关,应避免混淆。冷冻电镜是一种可以使生物大分子尽量维持在生物体内活性状态下,并被测定其原子级别高分辨率结构的技术。本文基于它,详细分析了组成 NEXT 复合物的核心蛋白 MTR4、RBM7 和 ZCCHC8 的结构及组装关系,包括它们所形成的复合物,结合底物 RNA 的通道。并结合其他分子实验,包括突变体细胞系构建、免疫沉淀、RNA表达谱测序等,分析和确认了它们在识别底物 RNA 过程中的作用。对 ZCCHC8-ROS1 融合等突变形式,对相应酶活性的影响,以及所导致的表型或疾病发生,也做了相应的研究和讨论。本文应该算是一篇典型的结构生物学研究文章,所研究的内容,属于普遍存在于所有真核生物与古菌生物的基础生物学问题,具有教科书级的重要意义。
IF:45.500Q1 Cell, 2022-06-09. DOI: 10.1016/j.cell.2022.04.016 PMID: 35688134
Abstract:
RNA quality control relies on co-factors and adaptors to identify and prepare substrates for degradation by ribonucleases such as the 3' to 5' ribonucleolytic RNA exosome. Here, we determined cryogenic … >>>
RNA quality control relies on co-factors and adaptors to identify and prepare substrates for degradation by ribonucleases such as the 3' to 5' ribonucleolytic RNA exosome. Here, we determined cryogenic electron microscopy structures of human nuclear exosome targeting (NEXT) complexes bound to RNA that reveal mechanistic insights to substrate recognition and early steps that precede RNA handover to the exosome. The structures illuminate ZCCHC8 as a scaffold, mediating homodimerization while embracing the MTR4 helicase and flexibly anchoring RBM7 to the helicase core. All three subunits collaborate to bind the RNA, with RBM7 and ZCCHC8 surveying sequences upstream of the 3' end to facilitate RNA capture by MTR4. ZCCHC8 obscures MTR4 surfaces important for RNA binding and extrusion as well as MPP6-dependent recruitment and docking onto the RNA exosome core, interactions that contribute to RNA surveillance by coordinating RNA capture, translocation, and extrusion from the helicase to the exosome for decay. <<<
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919.
龙海晨 (2022-06-10 12:26):
#paper Ropio J, Chebly A, Ferrer J, Prochazkova-Carlotti M, Idrissi Y, Azzi-Martin L, Cappellen D, Pham-Ledard A, Soares P, Merlio JP, Chevret E. Reliable blood cancer cells' telomere length evaluation by qPCR. Cancer Med. 2020 May;9(9):3153-3162. doi: 10.1002/cam4.2816. Epub 2020 Mar 6. PMID: 32142223; PMCID: PMC7196062.题目:Reliable blood cancer cells' telomere length evaluation by qPCR 端粒缩短与一系列不同的人类疾病有关,因此需要可靠的测量方法来揭示这种关联。在众多端粒长度测量方法中,qPCR被认为是一种易于进行且经济高效的方法,可以研究DNA含量较低的样本。文章采用采用相对和绝对qPCR方法检测癌细胞端粒长度。qPCR数据与terminal restriction fragment (TRF),(端粒长度测量“金标准”)测量值进行比较。从每个样品(细胞系、患者和健康供体)的重复反应中收集数据。当重复中 Ct 的标准偏差低于 0.5 时,接受重复值。qPCR 估计的平均细胞系端粒长度(4.320 ± 0.143 kb)与 TRF 估计的(5.652 kb).相似,P = 0.5040。对基于 qPCR 的技术,测量端粒长度要求使用高质量的 DNA,当DNA降解严重时,QPCR的测量不准确。如果QPCR法测量端粒长度的细胞是癌细胞,那关键点在于选择合适的参考基因,因为癌细胞的增殖不像正常细胞那样规范,癌细胞增殖时有些基因会丢失,癌细胞还会积累遗传和染色体异常。
IF:2.900Q2 Cancer medicine, 2020-05. DOI: 10.1002/cam4.2816 PMID: 32142223 PMCID:PMC7196062
Abstract:
BACKGROUND: Telomere shortening is linked to a range of different human diseases, hence reliable measurement methods are needed to uncover such associations. Among the plethora of telomere length measurement methods, … >>>
BACKGROUND: Telomere shortening is linked to a range of different human diseases, hence reliable measurement methods are needed to uncover such associations. Among the plethora of telomere length measurement methods, qPCR is reported as easy to conduct and a cost-effective approach to study samples with low DNA amounts.METHODS: Cancer cells' telomere length was evaluated by relative and absolute qPCR methods.RESULTS: Robust and reproducible telomere length measurements were optimized taking into account a careful reference gene selection and by knowing the cancer cells ploidy. qPCR data were compared to "gold standard" measurement from terminal restriction fragment (TRF).CONCLUSIONS: Our study provides guidance and recommendations for accurate telomere length measurement by qPCR in cancer cells, taking advantage of our expertise in telomere homeostasis investigation in primary cutaneous T-cell lymphomas. Furthermore, our data emphasize the requirement of samples with both, high DNA quality and high tumor cells representation. <<<
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颜林林 (2022-06-10 07:29):
#paper doi:10.1186/1471-2199-7-3 BMC Molecular Biology, 2006, The RIN: an RNA integrity number for assigning integrity values to RNA measurements. 在分子生物学实验中,涉及到RNA质控,评估其分子完整性,最重要且最广泛使用的指标,当属RIN值(RNA integrity Number)。16年前的这篇文章,正是关于RIN值算法及建立过程的工作。Agilent、Roche 和 Quantiom bioinformatics 等单位参与了此项工作。该算法成为至今仍在使用的 2100 生物分析仪的标配和重要输出指标。在RIN值之前,通常使用 28S和18S rRNA的比值来进行评估(一般要求达到至少2.0),而这个比值受电泳胶图展示和手工测量的影响,经常不够稳定,在实验室之间存在很大差异,更重要的,其与RNA分子的完整性经常并不相关。于是,本文开发了一套方法,使用毛细管电泳技术,采集到样本中的所有不同长度核酸分子的丰度信息,由此自动提取特征,基于贝叶斯方法和神经网络算法,构建回归模型,并最终选择出估计RNA完整性的特征组合,并计算出RIN值(取值1-10,1代表完全降解,10代表无降解)。研究者从人、大鼠、小鼠的不同器官组织,以及各类细胞系中,分别提取了RNA,共收集了1208份样本,这其中主要是未降解的完整样本和完全降解的样本,此外也包括了足够的部分降解的样本。通过不同比例的组合将其混合,构造了一套包含各种不同降解程度的实际样本,用于产出数据、提取特征后构造分类模型,以及对该分类模型(模型输出为RIN值,分别为1-10的整数)的性能评估。同时也将模型算法计算得到的rRNA比值、RIN值,与(4个看家基因的)rtPCR数据进行了对比,确认其对RNA质量和完整程度的代表性。
BMC molecular biology, 2006-Jan-31. PMID: 16448564 PMCID:PMC1413964
Abstract:
BACKGROUND: The integrity of RNA molecules is of paramount importance for experiments that try to reflect the snapshot of gene expression at the moment of RNA extraction. Until recently, there … >>>
BACKGROUND: The integrity of RNA molecules is of paramount importance for experiments that try to reflect the snapshot of gene expression at the moment of RNA extraction. Until recently, there has been no reliable standard for estimating the integrity of RNA samples and the ratio of 28S:18S ribosomal RNA, the common measure for this purpose, has been shown to be inconsistent. The advent of microcapillary electrophoretic RNA separation provides the basis for an automated high-throughput approach, in order to estimate the integrity of RNA samples in an unambiguous way.METHODS: A method is introduced that automatically selects features from signal measurements and constructs regression models based on a Bayesian learning technique. Feature spaces of different dimensionality are compared in the Bayesian framework, which allows selecting a final feature combination corresponding to models with high posterior probability.RESULTS: This approach is applied to a large collection of electrophoretic RNA measurements recorded with an Agilent 2100 bioanalyzer to extract an algorithm that describes RNA integrity. The resulting algorithm is a user-independent, automated and reliable procedure for standardization of RNA quality control that allows the calculation of an RNA integrity number (RIN).CONCLUSION: Our results show the importance of taking characteristics of several regions of the recorded electropherogram into account in order to get a robust and reliable prediction of RNA integrity, especially if compared to traditional methods. <<<
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